PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
SELECT ?item ?itemLabel ?url WHERE {
  ?item wdt:P856 ?url .
  FILTER ( CONTAINS( LCASE( STR( ?url ) ) , "twitter" ) ) OPTIONAL {
    ?item rdfs:label ?itemLabel .
    FILTER ( LANG( ?itemLabel ) = "en" )
  }
}
ORDER BY ?item
LIMIT 10000

Got 69 rows and 3 columns, showing the first 5 and last 5 rows below:
| item                                          | itemLabel                          | url                                                                                |
| --------------------------------------------- | ---------------------------------- | ------------------------------------------------------------------------------------------------------------------------- |
| rain museum (wd:Q100138485)                   | rain museum (en)                   | <https://mobile.twitter.com/regenmuseum>                                                                                |
| Luther E. Vann (wd:Q100208149)                | Luther E. Vann (en)                | <https://www.author-poet-aberjhani.info/httpwwwauthor-poet-aberjhaniinfotwitter-tweets-news-notes/category/luther-e-vann> |
| Twemoji (wd:Q100601019)                       | Twemoji (en)                       | <https://twemoji.twitter.com/>                                                                                |
| Alaa Maan (wd:Q100969271)                     | Alaa Maan (en)                     | <https://twitter.com/alaamaan1?lang=en>                                                                                |
| West Wittering Parish Council (wd:Q104383379) | West Wittering Parish Council (en) | <http://www.westwitteringparishcouncil.gov.uk>                                                                            |
| ...                                           | ...                                | ...                                                                                |
| Ross Patterson (wd:Q7369567)                  | Ross Patterson (en)                | <http://https://twitter.com/StJamesStJames>                                                                               |
| Tween (wd:Q7857509)                           | Tween (en)                         | <https://sites.google.com/site/tweentwitterclient/>                                                                       |
| Twitterfall (wd:Q7858629)                     | Twitterfall (en)                   | <http://www.twitterfall.com/>                                                                                |
| women to drive movement (wd:Q8031633)         | women to drive movement (en)       | <https://twitter.com/hashtag/women2drive>                                                                                |
| X Pro (wd:Q931346)                            | X Pro (en)                         | <http://tweetdeck.twitter.com>                                                                                |

I ran the query above against Wikidata. It returned 69 items whose official website (wdt:P856) contains the string "twitter" (case-insensitive). The query returns the item IRI (?item), the English rdfs:label (if available), and the URL. Example results include:
- wd:Q100138485 — rain museum — https://mobile.twitter.com/regenmuseum
- wd:Q100601019 — Twemoji — https://twemoji.twitter.com/
- wd:Q100969271 — Alaa Maan — https://twitter.com/alaamaan1?lang=en
- wd:Q7858629 — Twitterfall — http://www.twitterfall.com/
- wd:Q8031633 — women to drive movement — https://twitter.com/hashtag/women2drive
- wd:Q931346 — X Pro — http://tweetdeck.twitter.com
You can run the SPARQL query above to retrieve the full list of items and their URLs.

Which items have an official website URL that contains the string "twitter"?

[System]
You are a question answering assistant. Your job is to generate a SPARQL query to answer a given user question.

You have access to the following knowledge graphs:
wikidata at https://qlever.cs.uni-freiburg.de/api/wikidata-sebastian

You are provided with some general notes:
No notes available

You can use the following SPARQL prefixes implicitly in all functions:
cc: <http://creativecommons.org/ns#
data: <https://www.wikidata.org/wiki/Special:EntityData/
dct: <http://purl.org/dc/terms/
geo: <http://www.opengis.net/ont/geosparql#
geof: <http://www.opengis.net/def/function/geosparql/
imdb: <https://www.imdb.com/
math: <http://www.w3.org/2005/xpath-functions/math#
ontolex: <http://www.w3.org/ns/lemon/ontolex#
owl: <http://www.w3.org/2002/07/owl#
p: <http://www.wikidata.org/prop/
pq: <http://www.wikidata.org/prop/qualifier/
pqn: <http://www.wikidata.org/prop/qualifier/value-normalized/
pqv: <http://www.wikidata.org/prop/qualifier/value/
pr: <http://www.wikidata.org/prop/reference/
prn: <http://www.wikidata.org/prop/reference/value-normalized/
prov: <http://www.w3.org/ns/prov#
prv: <http://www.wikidata.org/prop/reference/value/
ps: <http://www.wikidata.org/prop/statement/
psn: <http://www.wikidata.org/prop/statement/value-normalized/
psv: <http://www.wikidata.org/prop/statement/value/
qfn: <http://qlever.cs.uni-freiburg.de/function#
ql: <http://qlever.cs.uni-freiburg.de/builtin-functions/
qlss: <https://qlever.cs.uni-freiburg.de/spatialSearch/
rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#
rdfs: <http://www.w3.org/2000/01/rdf-schema#
ref: <http://www.wikidata.org/reference/
s: <http://www.wikidata.org/entity/statement/
schema: <http://schema.org/
skos: <http://www.w3.org/2004/02/skos/core#
v: <http://www.wikidata.org/value/
wd: <http://www.wikidata.org/entity/
wdno: <http://www.wikidata.org/prop/novalue/
wdt: <http://www.wikidata.org/prop/direct/
wdtn: <http://www.wikidata.org/prop/direct-normalized/
wikibase: <http://wikiba.se/ontology#
xsd: <http://www.w3.org/2001/XMLSchema#
foaf: <http://xmlns.com/foaf/0.1/
dc: <http://purl.org/dc/elements/1.1/
gn: <http://www.geonames.org/ontology#
bd: <http://www.bigdata.com/rdf#
hint: <http://www.bigdata.com/queryHints#
qb: <http://purl.org/linked-data/cube#
void: <http://rdfs.org/ns/void#

You should follow a step-by-step approach to generate the SPARQL query:
1. Determine possible entities and properties implied by the user question.
2. Search for the entities and properties in the knowledge graphs. Where applicable, constrain the searches with already identified entities and properties.
3. Gradually build up the SPARQL query using the identified entities and properties. Start with simple queries and add more complexity as needed. Execute intermediate queries to get feedback and to verify your assumptions. You may need to refine or rethink your current plan based on the query results and go back to step 2 if needed, possibly multiple times.
4. Use the answer or cancel function to finalize your answer and stop the generation process.

Additional rules:
1. Explain your thought process before and after each step and function call.
2. Do not just use or make up entity or property identifiers without verifying their existence in the knowledge graphs first.
3. Always execute your final SPARQL query before giving an answer to make sure it returns the expected results.
4. The SPARQL query should always return the actual identifiers / IRIs of the items in its result. It additionally may return labels or other human-readable information, but they are optional and should be put within optional clauses unless explicitly requested by the user.
5. Do not stop early if there are still obvious improvements to be made to the SPARQL query. For example, keep refining your SPARQL query if its result contains irrelevant items or is missing items you expected.
6. Do not perform additional computation (e.g. filtering, sorting, calculations) on the result of the SPARQL query to determine the answer. All computation should be done solely within SPARQL.
7. For questions with a "True" or "False" answer the SPARQL query should be an ASK query.
8. Do not use 'SERVICE wikibase:label { bd:serviceParam wikibase:language ...' in SPARQL queries. It is not SPARQL standard and unsupported by the used QLever SPARQL endpoints. Use rdfs:label or similar properties to get labels instead.

[User] Which items have an official website URL that contains the string "twitter"?

[Assistant] Step 1: I'll verify the property for "official website" in Wikidata (expected to be P856). I'll search for properties matching "official website". I'll call the property search tool next.

[Tool]
Top 10 property alternatives:
1. official website, also known as site (official), site official, URL, URL (official), URL official (wd:P856 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): URL of the official page of an item (current or former). Usage: ...but see the "Hijacked or dead websites" section of the Talk page, subproperty of URL
2. official shop URL, also known as website, web shop URL, URL shop, official store website, store URL (wd:P10225 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): official URL where the agent sells products/merchandise, subproperty of official website
3. official wiki URL, also known as official wiki, wiki website, wiki URL, wiki, official wiki website (wd:P12203 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): URL of the official wiki for the item, subproperty of URL
4. house publication, also known as official media, publishes, publication, organization publication, organisation publication (wd:P2813 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): media that speaks for an organization or a movement, and that is usually edited by its members
5. sitemap URL, also known as sitemap, sitemap xml, site map URL (wd:P11212 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): URL to the sitemap of the subject's official website, subproperty of URL
6. title of broader work, also known as container title, website title (wd:P6333 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): title of website, journal or other work in which an article (or ...is published in. Use "published in" (P1433) instead if possible.
7. login URL, also known as sign-in URL, sign in URL, sign-in page, sign in page, login page URL (wd:P11903 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): URL of a webpage used to log into a service, subproperty of URL
8. topic's main Wikimedia portal, also known as portal, main portal (wd:P1151 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): Wikimedia portal associated with this topic
9. official jobs URL, also known as jobs URL, official careers website, official careers URL, jobs website, careers website (wd:P10311 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): web page for jobs an employer offers, subproperty of URL
10. official list URL (wd:P12388 as psv/psn/prn/prv/pqn/p/pq/wdtn/wdt/pqv/ps/pr): URL of a website listing instances of the subject, maintained by the authority on the subject

[Assistant] Now I'll run a SPARQL query to find items with the "official website" property (P856) whose URL contains "twitter" (case-insensitive). I'll request the item IRI, its English rdfs:label (optional), and the URL.

[Tool]
Got 69 rows and 3 columns, showing the first 5 and last 5 rows below:
| item                                          | itemLabel                          | url                                                                                |
| --------------------------------------------- | ---------------------------------- | ------------------------------------------------------------------------------------------------------------------------- |
| rain museum (wd:Q100138485)                   | rain museum (en)                   | <https://mobile.twitter.com/regenmuseum>                                                                                |
| Luther E. Vann (wd:Q100208149)                | Luther E. Vann (en)                | <https://www.author-poet-aberjhani.info/httpwwwauthor-poet-aberjhaniinfotwitter-tweets-news-notes/category/luther-e-vann> |
| Twemoji (wd:Q100601019)                       | Twemoji (en)                       | <https://twemoji.twitter.com/>                                                                                |
| Alaa Maan (wd:Q100969271)                     | Alaa Maan (en)                     | <https://twitter.com/alaamaan1?lang=en>                                                                                |
| West Wittering Parish Council (wd:Q104383379) | West Wittering Parish Council (en) | <http://www.westwitteringparishcouncil.gov.uk>                                                                            |
| ...                                           | ...                                | ...                                                                                |
| Ross Patterson (wd:Q7369567)                  | Ross Patterson (en)                | <http://https://twitter.com/StJamesStJames>                                                                               |
| Tween (wd:Q7857509)                           | Tween (en)                         | <https://sites.google.com/site/tweentwitterclient/>                                                                       |
| Twitterfall (wd:Q7858629)                     | Twitterfall (en)                   | <http://www.twitterfall.com/>                                                                                |
| women to drive movement (wd:Q8031633)         | women to drive movement (en)       | <https://twitter.com/hashtag/women2drive>                                                                                |
| X Pro (wd:Q931346)                            | X Pro (en)                         | <http://tweetdeck.twitter.com>                                                                                |

[Assistant] Now I'll run the final SPARQL query (no tight LIMIT) to retrieve all items with wdt:P856 containing "twitter", returning the item IRI, its English rdfs:label (if any), and the URL.

[Tool]
Got 69 rows and 3 columns, showing the first 5 and last 5 rows below:
| item                                          | itemLabel                          | url                                                                                |
| --------------------------------------------- | ---------------------------------- | ------------------------------------------------------------------------------------------------------------------------- |
| rain museum (wd:Q100138485)                   | rain museum (en)                   | <https://mobile.twitter.com/regenmuseum>                                                                                |
| Luther E. Vann (wd:Q100208149)                | Luther E. Vann (en)                | <https://www.author-poet-aberjhani.info/httpwwwauthor-poet-aberjhaniinfotwitter-tweets-news-notes/category/luther-e-vann> |
| Twemoji (wd:Q100601019)                       | Twemoji (en)                       | <https://twemoji.twitter.com/>                                                                                |
| Alaa Maan (wd:Q100969271)                     | Alaa Maan (en)                     | <https://twitter.com/alaamaan1?lang=en>                                                                                |
| West Wittering Parish Council (wd:Q104383379) | West Wittering Parish Council (en) | <http://www.westwitteringparishcouncil.gov.uk>                                                                            |
| ...                                           | ...                                | ...                                                                                |
| Ross Patterson (wd:Q7369567)                  | Ross Patterson (en)                | <http://https://twitter.com/StJamesStJames>                                                                               |
| Tween (wd:Q7857509)                           | Tween (en)                         | <https://sites.google.com/site/tweentwitterclient/>                                                                       |
| Twitterfall (wd:Q7858629)                     | Twitterfall (en)                   | <http://www.twitterfall.com/>                                                                                |
| women to drive movement (wd:Q8031633)         | women to drive movement (en)       | <https://twitter.com/hashtag/women2drive>                                                                                |
| X Pro (wd:Q931346)                            | X Pro (en)                         | <http://tweetdeck.twitter.com>                                                                                |

[Assistant] I'll run the final SPARQL query (ordered and with a high limit) to retrieve all items with wdt:P856 containing "twitter", returning item IRI, English label (if any), and the URL. This verifies the full result set before reporting.

[Tool]
Got 69 rows and 3 columns, showing the first 5 and last 5 rows below:
| item                                          | itemLabel                          | url                                                                                |
| --------------------------------------------- | ---------------------------------- | ------------------------------------------------------------------------------------------------------------------------- |
| rain museum (wd:Q100138485)                   | rain museum (en)                   | <https://mobile.twitter.com/regenmuseum>                                                                                |
| Luther E. Vann (wd:Q100208149)                | Luther E. Vann (en)                | <https://www.author-poet-aberjhani.info/httpwwwauthor-poet-aberjhaniinfotwitter-tweets-news-notes/category/luther-e-vann> |
| Twemoji (wd:Q100601019)                       | Twemoji (en)                       | <https://twemoji.twitter.com/>                                                                                |
| Alaa Maan (wd:Q100969271)                     | Alaa Maan (en)                     | <https://twitter.com/alaamaan1?lang=en>                                                                                |
| West Wittering Parish Council (wd:Q104383379) | West Wittering Parish Council (en) | <http://www.westwitteringparishcouncil.gov.uk>                                                                            |
| ...                                           | ...                                | ...                                                                                |
| Ross Patterson (wd:Q7369567)                  | Ross Patterson (en)                | <http://https://twitter.com/StJamesStJames>                                                                               |
| Tween (wd:Q7857509)                           | Tween (en)                         | <https://sites.google.com/site/tweentwitterclient/>                                                                       |
| Twitterfall (wd:Q7858629)                     | Twitterfall (en)                   | <http://www.twitterfall.com/>                                                                                |
| women to drive movement (wd:Q8031633)         | women to drive movement (en)       | <https://twitter.com/hashtag/women2drive>                                                                                |
| X Pro (wd:Q931346)                            | X Pro (en)                         | <http://tweetdeck.twitter.com>                                                                                |

[Assistant]
Step-by-step summary of what I did:
1. Identified the Wikidata property for "official website" (P856).
2. Ran a SPARQL query to find items with wdt:P856 where the URL contains the substring "twitter" (case-insensitive).
3. Verified the results (the query returned 69 items). I included the final SPARQL query below and a short summary of results with a few examples.

Now I'll provide the final SPARQL query and the result summary.

[Tool] Stopped generation process